Percussion tool



Aug. 20, 1940.l ,Y R.- vAsARb PERCUSSION TOOL Filed June 27, 1939.

Patented Aug. 20, l194)() UNITED STATES My invention relates topercussion or hammering tools in which a drill head is subjectedto blowsproduced by an impact element and has particular reference to tools inwhich the impact element is under action of centrifugal force.

The object of my invention is to provide a percussion tool having twoimpact elements operating one after the other, thereby producing a rapidsuccession of blows against the end of a drill head.

My invention is more fully described in the accompanying specication anddrawing in which- Fig. lis a sectional elevational view of my tool:

Fig. 2 is a transverse sectional view of the; same;

and

Fig. 3 is an enlarged view-of a rotating disc with the impact element.

The tool consists of a casing I with a suitable handle and a cover 2.lThe casing ,and the cover I0 are provided with recesses for ballbearings 3, supporting trunnions 4 extending from discs 3 and 9. Thetrunnion 4 of the disc 8 is connected to a flexible shaft 5 rotativelysupported ina.

bushing 6 fitted in a central extension of theV 5 casing I. The discsare provided with spiral guiding grooves I5 opposite each other,extending tangentially to a circle K near the periphery of the discs andcurving toward the centers of the discs Where the grooves almost mergeinto' each other.

The grooves represent guiding channels for cyl-- indrical impactelements I0, the latter being free to slide in the grooves toward theirperiphery by the action of centrifugal force. The discs 8 and 9 arejoined together by bolts 1.

.5:5 The casing has a tangential extension I4 'with y' a bore for adrill head or similar tool I2. The latter has an enlargement on the end-engaging an adjustable bushing I3 in the bore. An impact plunger I I isplaced in the bore on topof the drill head, the axis of the plungerpassing ,thangentially to the 'circle K so that the impact elements I0can strike the end of the plunger when the shaft is rotating. 'Iheimpact throws the elements I0 back toward the center of the discs, thecentrifugal force returning them immediately to ithe peripheralposition.` The force lof Vthe blowsb'can be regulated by ,adjusting theposition of the drill head and plunger, the vadjustment beingaccomplished by shifting the position of the bushing I3. With myconstruction it is possible `to use two impact elements,thereby-doubling the speedof the operation.l The tangential arrangementoiy the peripheral portions of the grooves, while enabling the impactelements to deliver axial blows, increases the operating speed of theimpact ele- `,PATENT oI-FICE Richard Vasard, Tallinn, EstoniaApplication June 27, 1939, Serial No. 281,498 In Estonia May 2, 41939 l3 Clams. (QL125-33).

cansan REISSU'D I DEG 1 6 1941' ments by adding the component of th'evelocity due to the centrifugal force to the angular velocity .of thecircle K.

I claim:

1. A percussion tool comprising a casing having a centrally positionedextension at the side, a shaft journaled in the extension adapted to beconnected toa source of power, a plate in the casing attached to theinner end of the shaft, a second plate in the casing in a spacedparallel rela- 10 tion to the rst plate, the plates having at theirinner sides curved bottomed grooves opposite each other extending fromthe outer portions of the plates substantially to the axis of theirrotation, cylindrical members slidably supported at their ll l ends inthe grooves, means to support the second plate on the first plate, saidmeans extending between intermediate portions of the discs outside thegrooves, a tubular .tangential extension on the i casing and a plungerslidably supported in the n tangential extension, the cylindricalmembers being adapted to successively strike the inner end of theplunger when the shaft is rotated, the tangential extension beingadapted to removably support a drilling tool in an operative contactwith 2li the plunger.

v2. A percussion tool comprising a casing having a centrally positionedextension'at the side, a shaft journaled in the extension adapted to beconnected to a source of power, a plate in the 30 casing attachedto theinner end of theshaft, a second plate in the casing in a spaced parallelrelation to the iirstv plate,` the plates having at their inner sidesarc-like grooves opposite each otherand extending from the peripheralportions of the plates substantially to their centers, straightcylindrical members slidably supported in the grooves and abutting bytheir ends the bottoms of the grooves, bolts attaching the second plateto thefirst plate and passing through 4| the plates at points at the'sides of the grooves, a tubular tangential extension on the casing and aplunger slidably supported in the tangential extension, the cylindricalmembers being adapted to successively strike the inner end of theplunger 4| when the 4shaft-is rotated, the tangential extension beingadapted to removably support a drilling tool in an operative contactwith the `plunger.`

3. A percussion tool comprising a casing having a centrally positionedextension 'at the side, a 50 shaft journaled in the `extension adaptedto be connected to a source-'of power, a plate'in the casing attached tothe inner end of the shaft, a second plate in thercasing in a spacedparallel relation to the iirst plate, the plates having at u their innersides curved bottomed grooves opposite each other extending from theouter portions of the platesv substantially to the axis of theirrotation, cylindrical members slidably supported at their ends in thegrooves, means to sunport the #second plate on the rst plate, said meansextending between intermediate portions of the discs outside thegrooves, a tubular tangential extension on the casing, a plungerslidably sup- 10 ported in the tangential extension, the cylinV plunger.

RICHARD VASARD.

